Simón Guerrero

Background/Objectives: Morin is the first flavonoid isolated from plants in the Moraceae family and has been reported to exhibit anticancer and antioxidant activity. It is classified as a Class IV compound in the Biopharmaceutical Classification System due to its low water solubility and low permeability. This study aimed to develop and characterize morin-loaded liposomes composed of DPPC and cholesterol to improve their stability and anticancer activity. Methods: Liposomes were prepared by thin-film hydration and then processed by bath sonication, probe sonication, or membrane extrusion to control vesicle size. Formulations were characterized by hydrodynamic diameter, polydispersity index (PDI), zeta potential, encapsulation efficiency (EE), and colloidal stability over 7 days at 37 °C. The cytotoxic effects of free and encapsulated morin were evaluated in tumor (MDA-MB-231, B16F10) and non-tumor (NIH-3T3, HEK-293T) cell lines. Results: Extrusion yielded the most homogeneous liposomes (PDI = 0.2, size ≈ 90 nm), whereas sonication methods produced larger, more polydisperse vesicles. EE ranged from 11–17%, with no significant differences among methods. Free morin degraded by 40% at 37 °C after 7 days, whereas liposomal encapsulation significantly reduced degradation, preserving 82–89% of the compound. At a morin equivalent of 3.4 µM, the bath-sonicated formulation reduced viability to approximately 65% in MDA-MB-231 cells and 70% in B16F10 cells, whereas viability remained approximately 86% in NIH-3T3 cells and 82% in HEK-293T cells. All formulations maintained colloidal stability over the study period. In cytotoxicity assays, free morin showed minimal activity, whereas liposomal formulations significantly enhanced antiproliferative effects against cancer cells. Conclusions: These findings demonstrate that DPPC/cholesterol liposomes effectively stabilize morin and improve its bioactivity, representing a promising strategy for delivering this flavonoid in anticancer therapies.

Gold nanoparticles (AuNPs) are promising peptide carriers whose size and anisotropic morphology may influence their interactions with antigen-presenting cells. However, current knowledge of the morphology-dependent effects of AuNPs and the role of peptide design in human macrophage responses remains incomplete. Furthermore, most studies have been performed in THP-1-derived macrophages as the main in vitro macrophage-like model, despite human primary macrophages (HPMs) providing a more physiologically representative system. Anisotropic AuNPs with two morphologies, nanorods (AuNRs) and nanostars (AuNSs), each synthesized in two sizes, were characterized and conjugated to three influenza M2 T-cell-epitope constructs containing CD4+ (P1) and CD8+ T-cell epitopes (P2), individually, and both combined in a single multiepitope construct (P3), optimized for intracellular processing using a novel bioinformatics tool coupled to Predivac 3.0. THP-1-derived macrophages and HPMs were exposed to these nanoconjugates at a fixed particle number concentration of 10 pM for 24 h and assessed for mitochondrial activity, cell death, reactive oxygen species, endolysosomal acidification, proteasome activity, and cathepsin B activity. The identity of the nanoparticle carrier, defined by its geometry together with its specific surface chemistry, rather than the type of conjugated peptide, dominated the cellular response. AuNRs, particularly long rods, reduced mitochondrial activity, increased cell death, and enhanced bulk 20S proteasome activity in both models, even though at equal particle number they delivered 21- to 53-fold less gold mass and 6- to 12-fold less geometric surface area than AuNSs. The stimulatory effect induced by AuNRs-P1 and AuNRs-P2 on the proteasomal system may be associated with their specific peptide design features. By contrast, AuNSs preserved viability, maintained low oxidative stress, and produced strong acidification signals consistent with efficient trafficking to endolysosomal compartments; P2 and P3 conjugation further improved cytocompatibility and increased cathepsin B activity. HPMs were consistently more tolerant than THP-1 macrophages. The morphology-surface chemistry identity of the AuNP carrier is a key determinant of macrophage compatibility and of the relative engagement of the two degradative compartments assayed here. Functionalized AuNSs, especially P2- and P3-nanoconjugates, showed the best balance among biocompatibility, endolysosomal trafficking, and cathepsin B engagement. The proposed correspondence with MHC class I versus class II antigen-processing routes is a mechanistically informed hypothesis that remains to be further validated experimentally.

Background: Natural products, such as propolis, are an important source of biologically active compounds with the potential to treat health disorders. Propolis is a well-known waxy resin recognized for its antimicrobial, immunomodulatory, and cytotoxic effects. Objective: In this study, we aimed to clarify the formation mechanism of propolis nanoparticles from the perspective of their stability and chemical composition. By evaluating the light absorption behaviour of the nanoparticles formed in different media and quantifying the polyphenols, we show that they are superficially hydrophobic nanoparticles with the capacity to encapsulate some polar compounds. Methods: Biological activity was evaluated by in vitro cell viability performed on NIH/3T3 fibroblasts incubated with 10, 100, and 1000 μg/mL of propolis nanoparticles for 48 hours. Results: The results show that nanoparticles are cytocompatible, with a proliferation effect. In contrast, the results of the viability of metastatic murine B16F10 cells indicate that a dose with a concentration of 5 μg/mL in the cell culture media is sufficient to stop the abnormal cell growth, having an antitumor effect. This effect might be related to the flavonoids present in the propolis nanoparticles. In vivo dermal irritability tests on New Zealand rabbits show that propolis nanoparticles' aqueous dissolution was non-irritant. Conclusion: According to the results obtained from this study, reducing the size of raw propolis down to nanoparticles and dispersing them in water solvents enhance its positive effects. The superficially hydrophobic propolis nanoparticles encapsulate active compounds such as polyphenols and flavonoids, which also confirms their ability to generate selective effects on the cells, depending on their nature.

Gold nanoparticles (AuNP) capped with biocompatible layers have functional optical, chemical, and biological properties as theranostic agents in biomedicine. The ferritin protein containing in situ synthesized AuNPs has been successfully used as an effective and completely biocompatible nanocarrier for AuNPs in human cell lines and animal experiments in vivo. Ferritin can be uptaken by different cell types through receptor-mediated endocytosis. Despite these advantages, few efforts have been made to evaluate the toxicity and cellular internalization of AuNP-containing ferritin nanocages. In this work, we study the potential of human heavy-chain (H) and light-chain (L) ferritin homopolymers as nanoreactors to synthesize AuNPs and their cytotoxicity and cellular uptake in different cell lines. The results show very low toxicity of ferritin-encapsulated AuNPs on different human cell lines and demonstrate that efficient cellular ferritin uptake depends on the specific H or L protein chains forming the ferritin protein cage and the presence or absence of metallic cargo. Cargo-devoid apoferritin is poorly internalized in all cell lines, and the highest ferritin uptake was achieved with AuNP-loaded H-ferritin homopolymers in transferrin-receptor-rich cell lines, showing more than seven times more uptake than apoferritin.

Este trabajo aborda la problemática representada por los micro y nanoplásticos (MP y NP, respectivamente) en las costas americanas del Océano Pacífico, desde la perspectiva de la Red Micro y Nano Allpa Pacha. Esta red está conformada por científicos de Chile, Perú, Costa Rica, Colombia, Ecuador, Panamá y México, quienes, preocupados por el impacto en el ambiente y su repercusión en la salud, decidieron establecer colaboraciones científicas internacionales para la geolocalización, monitoreo y caracterización de MP y NP presentes en las costas del Océano Pacífico en el continente americano. Se espera aportar datos basados en evidencias científicas y armonizados, que impacten en la enseñanza y en la planificación de medidas de control y regulación de estos contaminantes en nuestros países. En este trabajo se incluyen algunos aspectos de polímeros y plásticos, definiciones de MP’s y NP’s, y sus diversos impactos, la problemática de la toma de muestras, caracterización adecuada, entre otros. Unas de las conclusiones permitieron determinar que hay muchas características de los NP’s y MP’s sin investigar como la interacción con otros productos químicos, el impacto de la morfología en la biodisponibilidad, la formación de adherencias y liberación de las mismas durante su contacto con los compartimentos ambientales, la dependencia de su composición con su comportamiento y destino, entre otras. Asimismo, se determinó que todo aporte a la mitigación del problema de estos materiales debe incluir la concientización, la prevención y la reducción, mediante un enfoque integral de educación y capacitación, y considerando todos los actores de la sociedad, responsables de la problemática generada, bajo un enfoque de evidencia científica. Finalmente, se determinó que el tema aún está en su fase inicial, y la información es reiterativa y auto referenciada.

The Smoothened (SMO) receptor is the most druggable target in the Hedgehog (HH) pathway for anticancer compounds. However, SMO antagonists such as vismodegib rapidly develop drug resistance. In this study, new SMO antagonists having the versatile purine ring as a scaffold were designed, synthesised, and biologically tested to provide an insight to their mechanism of action. Compound 4s was the most active and the best inhibitor of cell growth and selectively cytotoxic to cancer cells. 4s induced cell cycle arrest, apoptosis, a reduction in colony formation and downregulation of PTCH and GLI1 expression. BODIPY-cyclopamine displacement assays confirmed 4s is a SMO antagonist. In vivo, 4s strongly inhibited tumour relapse and metastasis of melanoma cells in mice. In vitro, 4s was more efficient than vismodegib to induce apoptosis in human cancer cells and that might be attributed to its dual ability to function as a SMO antagonist and apoptosis inducer.

The inclusion compound (IC) of cyclodextrin (CD) containing the antitumor drug Methotrexate (MTX) as a guest molecule was obtained to increase the solubility of MTX and decrease its inherent toxic effects in nonspecific cells. The IC was conjugated with gold nanoparticles (AuNPs), obtained by a chemical method, creating a ternary intelligent delivery system for MTX molecules, based on the plasmonic properties of the AuNPs. Irradiation of the ternary system, with a laser wavelength tunable with the corresponding surface plasmon of AuNPs, causes local energy dissipation, producing the controlled release of the guest from CD cavities. Finally, cell viability was evaluated using MTS assays for β-CD/MTX and AuNPs + β-CD/MTX samples, with and without irradiation, against HeLa tumor cells. The irradiated sample of the ternary system AuNPs + β-CD/MTX produced a diminution in cell viability attributed to the photothermal release of MTX.

Stable and non-toxic fluorescent markers are gaining attention in molecular diagnostics as powerful tools for enabling long and reliable biological studies. Such markers should not only have a long half-life under several assay conditions showing no photo bleaching or blinking but also, they must allow for their conjugation or functionalization as a crucial step for numerous applications such as cellular tracking, biomarker detection and drug delivery. We report the functionalization of stable fluorescent markers based on nanodiamonds (NDs) with a bifunctional peptide. This peptide is made of a cell penetrating peptide and a six amino acids long β-sheet breaker peptide that is able to recognize amyloid β (Aβ) aggregates, a biomarker for the Alzheimer disease. Our results indicate that functionalized NDs (fNDs) are not cytotoxic and can be internalized by the cells. The fNDs allow ultrasensitive detection (at picomolar concentrations of NDs) of in vitro amyloid fibrils and amyloid aggregates in AD mice brains. The fluorescence of functionalized NDs is more stable than that of fluorescent markers commonly used to stain Aβ aggregates such as Thioflavin T. These results pave the way for performing ultrasensitive and reliable detection of Aβ aggregates involved in the pathogenesis of the Alzheimer disease.